Such crucible are known; for the manufacture of precision castings, the so-called "fine castings", they are charged with a block of the material for the casting, which is fused by electrical heating (a) resistance heating or an inductive heating). The tapping opening in the base is closed off by a small plate, the so-called "penny", until the contents of the crucible have been fused completely.
The crucible, which usually is rather thin-walled and comprises an impregnated, fibrous mineral material, is subjected in such operations to very severe stresses and is therefore suitable only for use with relatively limited charge weights of not more than about 5 kg.
It is therefore an object of the invention to improve a smelting crucible of the initially described type, so that it is also suitable for accommodating larger charge weights.